Implement basic IRC connection and message parsing

1 files changed, 167 insertions, 3 deletions

diff --git a/litterbox.c b/litterbox.c
index 2fa52fb..2b2736d 100644
--- a/litterbox.c
+++ b/litterbox.c
@@ -14,35 +14,152 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+#include <assert.h>
 #include <err.h>
 #include <sqlite3.h>
+#include <stdarg.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sysexits.h>
+#include <tls.h>
 #include <unistd.h>
 
 #include "database.h"
 
+static sqlite3 *db;
+static struct tls *client;
+static bool verbose;
+
+static void writeAll(const char *ptr, size_t len) {
+	while (len) {
+		ssize_t ret = tls_write(client, ptr, len);
+		if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) continue;
+		if (ret < 0) errx(EX_IOERR, "tls_write: %s", tls_error(client));
+		ptr += ret;
+		len -= ret;
+	}
+}
+
+static void format(const char *format, ...) {
+	char buf[1024];
+	va_list ap;
+	va_start(ap, format);
+	int len = vsnprintf(buf, sizeof(buf), format, ap);
+	va_end(ap);
+	assert((size_t)len < sizeof(buf));
+	if (verbose) printf("%s", buf);
+	writeAll(buf, len);
+}
+
+enum { ParamCap = 15 };
+struct Message {
+	char *time;
+	char *nick;
+	char *user;
+	char *host;
+	char *cmd;
+	char *params[ParamCap];
+};
+
+static struct Message parse(char *line) {
+	if (verbose) fprintf(stderr, "%s\n", line);
+	struct Message msg = {0};
+	if (line[0] == '@') {
+		char *tags = 1 + strsep(&line, " ");
+		while (tags) {
+			char *tag = strsep(&tags, ";");
+			char *key = strsep(&tag, "=");
+			if (!strcmp(key, "time")) msg.time = tag;
+		}
+	}
+	if (line[0] == ':') {
+		char *origin = 1 + strsep(&line, " ");
+		msg.nick = strsep(&origin, "!");
+		msg.user = strsep(&origin, "@");
+		if (origin) {
+			msg.host = origin;
+		} else {
+			msg.host = msg.nick;
+			msg.nick = NULL;
+		}
+	}
+	msg.cmd = strsep(&line, " ");
+	for (size_t i = 0; line && i < ParamCap; ++i) {
+		if (line[0] == ':') {
+			msg.params[i] = &line[1];
+			break;
+		}
+		msg.params[i] = strsep(&line, " ");
+	}
+	return msg;
+}
+
+typedef void Handler(struct Message *msg);
+
+static void handleCap(struct Message *msg) {
+	(void)msg;
+	format("CAP END\r\n");
+}
+
+static void handlePing(struct Message *msg) {
+	// TODO: Require params[0].
+	format("PONG :%s\r\n", msg->params[0]);
+}
+
+static const struct {
+	const char *cmd;
+	Handler *fn;
+} Handlers[] = {
+	{ "CAP", handleCap },
+	{ "PING", handlePing },
+};
+
+static void handle(struct Message msg) {
+	if (!msg.cmd) return;
+	for (size_t i = 0; i < ARRAY_LEN(Handlers); ++i) {
+		if (strcmp(msg.cmd, Handlers[i].cmd)) continue;
+		Handlers[i].fn(&msg);
+		break;
+	}
+}
+
 int main(int argc, char *argv[]) {
 	char *path = NULL;
 	bool init = false;
 	bool migrate = false;
 
+	bool insecure = false;
+	const char *host = NULL;
+	const char *port = "6697";
+
+	const char *nick = "litterbox";
+	const char *user = NULL;
+	const char *pass = NULL;
+
 	int opt;
-	while (0 < (opt = getopt(argc, argv, "d:im"))) {
+	while (0 < (opt = getopt(argc, argv, "!d:h:imn:p:u:vw:"))) {
 		switch (opt) {
+			break; case '!': insecure = true;
 			break; case 'd': path = optarg;
+			break; case 'h': host = optarg;
 			break; case 'i': init = true;
 			break; case 'm': migrate = true;
+			break; case 'n': nick = optarg;
+			break; case 'p': port = optarg;
+			break; case 'u': user = optarg;
+			break; case 'v': verbose = true;
+			break; case 'w': pass = optarg;
 			break; default:  return EX_USAGE;
 		}
 	}
+	if (!user) user = nick;
 
 	int flags = SQLITE_OPEN_READWRITE;
 	if (init) flags |= SQLITE_OPEN_CREATE;
 
-	sqlite3 *db = (path ? dbOpen(path, flags) : dbFind(flags));
+	db = (path ? dbOpen(path, flags) : dbFind(flags));
 	if (!db) errx(EX_NOINPUT, "database not found");
 
 	if (init) {
@@ -53,8 +170,55 @@ int main(int argc, char *argv[]) {
 		dbMigrate(db);
 		return EX_OK;
 	}
-
 	if (dbVersion(db) != DatabaseVersion) {
 		errx(EX_CONFIG, "database out of date; migrate with -m");
 	}
+
+	if (!host) errx(EX_USAGE, "host required");
+
+	client = tls_client();
+	if (!client) errx(EX_SOFTWARE, "tls_client");
+
+	struct tls_config *config = tls_config_new();
+	if (!config) errx(EX_SOFTWARE, "tls_config_new");
+
+	int error = tls_config_set_ciphers(config, "compat");
+	if (error) {
+		errx(EX_SOFTWARE, "tls_config_set_ciphers: %s", tls_config_error(config));
+	}
+	if (insecure) {
+		tls_config_insecure_noverifycert(config);
+		tls_config_insecure_noverifyname(config);
+	}
+
+	error = tls_configure(client, config);
+	if (error) errx(EX_SOFTWARE, "tls_configure: %s", tls_error(client));
+	tls_config_free(config);
+
+	error = tls_connect(client, host, port);
+	if (error) errx(EX_UNAVAILABLE, "tls_connect: %s", tls_error(client));
+
+	if (pass) format("PASS :%s\r\n", pass);
+	format("CAP REQ :server-time\r\n");
+	format("NICK :%s\r\nUSER %s 0 * :Litterbox\r\n", nick, user);
+
+	char buf[8191 + 512];
+	size_t len = 0;
+	for (;;) {
+		ssize_t ret = tls_read(client, &buf[len], sizeof(buf) - len);
+		if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) continue;
+		if (ret < 0) errx(EX_IOERR, "tls_read: %s", tls_error(client));
+		len += ret;
+
+		char *line = buf;
+		for (;;) {
+			char *crlf = memmem(line, &buf[len] - line, "\r\n", 2);
+			if (!crlf) break;
+			crlf[0] = '\0';
+			handle(parse(line));
+			line = crlf + 2;
+		}
+		len -= line - buf;
+		memmove(buf, line, len);
+	}
 }